Add additional_includes to C generator.

backends/c/src/config.rs

@@ -76,6 +76,8 @@ pub struct Config {
     pub directives: bool,
     /// Whether to write `#include <>` directives.
     pub imports: bool,
+    /// Additional `#include` lines in the form of `<item.h>`` or `"item.h"`.
+    pub additional_includes: Vec<String>,
     /// The `_X` in `#ifndef _X` to be used.
     pub ifndef: String,
     /// Multiline string with custom `#define` values.
@@ -107,6 +109,7 @@ impl Default for Config {
         Self {
             directives: true,
             imports: true,
+            additional_includes: vec![],
             file_header_comment: "// Automatically generated by Interoptopus.".to_string(),
             ifndef: "interoptopus_generated".to_string(),
             custom_defines: "".to_string(),

backends/c/src/writer.rs

@@ -34,6 +34,11 @@ pub trait CWriter {
         indented!(w, r#"#include <stdint.h>"#)?;
         indented!(w, r#"#include <stdbool.h>"#)?;
 
+        // Write any user supplied includes into the file.
+        for include in &self.config().additional_includes {
+            indented!(w, "#include {}", include)?;
+        }
+
         Ok(())
     }
 

examples/complex/bindings/c/example_complex.h

@@ -9,6 +9,7 @@ extern "C" {
 
 #include <stdint.h>
 #include <stdbool.h>
+#include <stdio.h>
 
 
 // Custom attribute.

examples/complex/tests/bindings.rs

@@ -39,6 +39,8 @@ fn bindings_c() -> Result<(), Error> {
     Generator::new(
         Config {
             ifndef: "example_complex".to_string(),
+            // Add an unneeded include for testing purposes.
+            additional_includes: vec!["<stdio.h>".into()],
             function_attribute: "__FUNCTION_ATTR ".to_string(),
             custom_defines,
             documentation: CDocumentationStyle::Inline,